Monday, May 3, 2010

Tiger

The tiger (Panthera tigris) is a member of the Felidae family and the largest and possibly most dangerous of the four "big cats" in the genus Panthera. Native to much of eastern and southern Asia, the tiger is an apex predator and an obligate carnivore. Reaching up to 3.3 metres (11 ft) in total length, weighing up to 300 kilograms (660 pounds), and having canines up to 4 inches long, the larger tiger subspecies are comparable in size to the biggest extinct felids. Aside from their great bulk and power, their most recognisable feature is a pattern of dark vertical stripes that overlays near-white to reddish-orange fur, with lighter underparts. The most numerous tiger subspecies is the Bengal tiger while the largest subspecies is the Siberian tiger.

Highly adaptable, tigers range from the Siberian taiga, to open grasslands, to tropical mangrove swamps. They are territorial and generally solitary animals, often requiring large contiguous areas of habitat that support their prey demands. This, coupled with the fact that they are indigenous to some of the more densely populated places on earth, has caused significant conflicts with humans. Of the nine subspecies of modern tiger, three are extinct and the remaining six are classified as endangered, some critically so. The primary direct causes are habitat destruction and fragmentation, and hunting. Their historical range once stretched from Mesopotamia and the Caucasus through most of South and East Asia. Today it has been radically reduced. While all surviving species are under formal protection, poaching, habitat destruction and inbreeding depression continue to threaten the species.

Tigers are among the most recognisable and popular of the world's charismatic megafauna. They have featured prominently in ancient mythology and folklore, and continue to be depicted in modern films and literature. Tigers appear on many flags and coats of arms, as mascots for sporting teams, and as the national animal of several Asian nations, including India

Naming and etymology:

The word "tiger" is taken from the Greek word "tigris", which is possibly derived from a Persian source meaning "arrow", a reference to the animal's speed and also the origin for the name of the Tigris river. In American English, "Tigress" was first recorded in 1611. It was one of the many species originally described, as Felis tigris, by Linnaeus in his 18th century work, Systema Naturae. The generic component of its scientific designation, Panthera tigris, is often presumed to derive from Greek pan- ("all") and theron ("beast"), but this may be a folk etymology. Although it came into English through the classical languages, panthera is probably of East Asian origin, meaning "the yellowish animal", or "whitish-yellow".

Biology and behaviour:

Territorial behaviour:

Tigers are essentially solitary and territorial animals. The size of a tiger's home range mainly depends on prey abundance, and, in the case of male tigers, on access to females. A tigress may have a territory of 20 square kilometres while the territories of males are much larger, covering 60–100 km2. The ranges of males tend to overlap those of several females.

The relationships between individuals can be quite complex, and it appears that there is no set "rule" that tigers follow with regards to territorial rights and infringing territories. For instance, although for the most part tigers avoid each other, both male and female tigers have been documented sharing kills. For instance, George Schaller observed a male tiger share a kill with two females and four cubs. Females are often reluctant to let males near their cubs, but Schaller saw that these females made no effort to protect or keep their cubs from the male, suggesting that the male might have been the father of the cubs. In contrast to male lions, male tigers will allow the females and cubs to feed on the kill first. Furthermore, tigers seem to behave relatively amicably when sharing kills, in contrast to lions, which tend to squabble and fight. Unrelated tigers have also been observed feeding on prey together. The following quotation is from Stephen Mills' book Tiger, as he describes an event witnessed by Valmik Thapar and Fateh Singh Rathore in Ranthambhore:

A dominant tigress they called Padmini killed a 250 kg (550-lb) male nilgai - a very large antelope. They found her at the kill just after dawn with her three 14-month-old cubs and they watched uninterrupted for the next ten hours. During this period the family was joined by two adult females and one adult male - all offspring from Padmini's previous litters and by two unrelated tigers, one female the other unidentified. By three o'clock there were no fewer than nine tigers round the kill.

When young female tigers first establish a territory, they tend to do so fairly close to their mother's area. The overlap between the female and her mother's territory tends to wane with increasing time. Males, however, wander further than their female counterparts, and set out at a younger age to mark out their own area. A young male will acquire territory either by seeking out a range devoid of other male tigers, or by living as a transient in another male's territory, until he is old and strong enough to challenge the resident male. The highest mortality rate (30-35% per year) amongst adult tigers occurs for young male tigers who have just left their natal area, seeking out territories of their own.

Male tigers are generally more intolerant of other males within their territory than females are of other females. For the most part, however, territorial disputes are usually solved by displays of intimidation, rather than outright aggression. Several such incidents have been observed, in which the subordinate tiger yielded defeat by rolling onto its back, showing its belly in a submissive posture. Once dominance has been established, a male may actually tolerate a subordinate within his range, as long as they do not live in too close quarters. The most violent disputes tend to occur between two males when a female is in oestrus, and may result in the death of one of the males, although this is actually a relatively rare occurrence.

To identify his territory, the male marks trees by spraying of urine and anal gland secretions, as well as marking trails with scat. Males show a grimacing face, called the Flehmen response, when identifying a female's reproductive condition by sniffing their urine markings. Like the other Panthera cats, tigers can roar. Tigers will roar for both aggressive and non-aggressive reasons. Other tiger vocal communications include moans, hisses, growls and chuffs.

Tigers have been studied in the wild using a variety of techniques. The populations of tigers were estimated in the past using plaster casts of their pugmarks. This method was found faulty and attempts were made to use camera trapping instead. Newer techniques based on DNA from their scat are also being evaluated. Radio collaring has also been a popular approach to tracking them for study in the wild.

Hunting and diet:

In the wild, tigers mostly feed on larger and medium sized animals. Sambar, gaur, chital, barasingha, wild boar, nilgai and both water buffalo and domestic buffalo are the tiger's favoured prey in India. Sometimes, they also prey on leopards, pythons, sloth bears and crocodiles. In Siberia the main prey species are manchurian wapiti, wild boar, sika deer, moose, roe deer, and musk deer. In Sumatra Sambar, muntjac, wild boar, and malayan tapir are preyed on. In the former Caspian tiger's range, prey included saiga antelope, camels, caucasian wisent, yak, and wild horses. Like many predators, they are opportunistic and will eat much smaller prey, such as monkeys, peafowls, hares, and fish.

Adult elephants are too large to serve as common prey, but conflicts between tigers and elephants do sometimes take place. A case where a tiger killed an adult Indian Rhinoceros has been observed. Young elephant and rhino calves are occasionally taken. Tigers also sometimes prey on domestic animals such as dogs, cows, horses, and donkeys. These individuals are termed cattle-lifters or cattle-killers in contrast to typical game-killers.

Old tigers, or those wounded and rendered incapable of catching their natural prey, have turned into man-eaters; this pattern has recurred frequently across India. An exceptional case is that of the Sundarbans, where healthy tigers prey upon fishermen and villagers in search of forest produce, humans thereby forming a minor part of the tiger's diet. Tigers will occasionally eat vegetation for dietary fiber, the fruit of the Slow Match Tree being favoured.

Tigers usually hunt at night. They generally hunt alone and ambush their prey as most other cats do, overpowering them from any angle, using their body size and strength to knock large prey off balance. Even with their great masses, tigers can reach speeds of about 49-65 kilometres per hour (35-40 miles per hour), although they can only do so in short bursts, since they have relatively little stamina; consequently, tigers must be relatively close to their prey before they break their cover. Tigers have great leaping ability; horizontal leaps of up to 10 metres have been reported, although leaps of around half this amount are more typical. However, only one in twenty hunts ends in a successful kill.

When hunting large prey, tigers prefer to bite the throat and use their forelimbs to hold onto the prey, bringing it to the ground. The tiger remains latched onto the neck until its prey dies of strangulation. By this method, gaurs and water buffalos weighing over a ton have been killed by tigers weighing about a sixth as much. With small prey, the tiger bites the nape, often breaking the spinal cord, piercing the windpipe, or severing the jugular vein or common carotid artery. Though rarely observed, some tigers have been recorded to kill prey by swiping with their paws, which are powerful enough to smash the skulls of domestic cattle, and break the backs of sloth bears.

During the 1980s, a tiger named "Genghis" in Ranthambhore National Park was observed frequently hunting prey through deep lake water,[66] a pattern of behaviour that had not been previously witnessed in over 200 years of observations. Moreover, he appeared to be extraordinarily successful for a tiger, with as many as 20% of hunts ending in a kill.

Reproduction:

Mating can occur all year round, but is generally more common between November and April. A female is only receptive for a few days and mating is frequent during that time period. A pair will copulate frequently and noisily, like other cats. The gestation period is 16 weeks. The litter size usually consists of around 3–4 cubs of about 1 kilogram (2.2 lb) each, which are born blind and helpless. The females rear them alone, sheltering them in dens such as thickets and rocky crevices. The father of the cubs generally takes no part in rearing them. Unrelated wandering male tigers may even kill cubs to make the female receptive, since the tigress may give birth to another litter within 5 months if the cubs of the previous litter are lost. The mortality rate of tiger cubs is fairly high - approximately half do not survive to be more than two years old.

There is generally a dominant cub in each litter, which tends to be male but may be of either sex.[66] This cub generally dominates its siblings during play and tends to be more active, leaving its mother earlier than usual. At 8 weeks, the cubs are ready to follow their mother out of the den, although they don't travel with her as she roams her territory until they are older. The cubs become independent around 18 months of age, but it is not until they are around 2–2½ years old that they leave their mother. Females reach sexual maturity at 3–4 years, whereas males reach sexual maturity at 4–5 years.

Over the course of her life, a female tiger will give birth to an approximately equal number of male and female cubs. Tigers breed well in captivity, and the captive population in the United States may rival the wild population of the world.

Interspecific predatory relationships:

Tigers may kill such formidable predators as leopards, pythons and even crocodiles on occasion, although predators typically avoid one another. When seized by a crocodile, a tiger will strike at the reptile's eyes with its paws. Though tigers have been known to kill crocodiles on land,there are cases where the crocodile has been observed killing a tiger in water. Leopards dodge competition from tigers by hunting in different times of the day and hunting different prey. With relatively abundant prey, tigers and leopards were seen to successfully coexist without competitive exclusion or inter-species dominance hierarchies that may be more common to the savanna. Tigers have been known to suppress wolf populations in areas where the two species coexist. Dhole packs have been observed to attack and kill tigers in disputes over food, though not usually without heavy losses. Lone golden jackals expelled from their pack have been known to form commensal relationships with tigers. These solitary jackals, known as kol-bahl, will attach themselves to a particular tiger, trailing it at a safe distance in order to feed on the big cat's kills. A kol-bahl will even alert a tiger to a kill with a loud pheal. Tigers have been known to tolerate these jackals: one report describes how a jackal confidently walked in and out between three tigers walking together a few feet away from each other. Siberian tigers and brown bears can be competitors and usually avoid confrontation; however, tigers will kill bear cubs and even some adults on occasion. Bears (Asiatic black bears and brown bears) make up 5-8% of the tiger's diet in the Russian Far East. There are also records of brown bears killing tigers, either in self defense or in disputes over kills. Some bears emerging from hibernation will try to steal tigers' kills, although the tiger will sometimes defend its kill. Sloth bears are quite aggressive and will sometimes drive young tigers away from their kills, although it is more common for Bengal tigers to prey on sloth bears.

Conservation efforts:

Poaching for fur and destruction of habitat have greatly reduced tiger populations in the wild. At the start of the 20th century, it is estimated there were over 100,000 tigers in the world but the population has dwindled to about 2,000 in the wild. Some estimates suggest the population is even lower, with some at less than 2,500 mature breeding individuals, with no subpopulation containing more than 250 mature breeding individuals.

India:

India is home to the world's largest population of tigers in the wild. According to the World Wildlife Fund, of the 3,500 tigers around the world, 1,400 are found in India. A major concerted conservation effort, known as Project Tiger, has been underway since 1973, which was initially spearheaded by Indira Gandhi. The fundamental accomplishment has been the establishment of over 25 well-monitored tiger reserves in reclaimed land where human development is categorically forbidden. The program has been credited with tripling the number of wild Bengal tigers from roughly 1,200 in 1973 to over 3,500 in the 1990s. However, a tiger census carried out in 2007, whose report was published on February 12, 2008, stated that the wild tiger population in India declined by 60% to approximately 1,411. It is noted in the report that the decrease of tiger population can be attributed directly to poaching.

Following the release of the report, the Indian government pledged $153 million to further fund the Project Tiger initiative, set-up a Tiger Protection Force to combat poachers, and fund the relocation of up to 200,000 villagers to minimise human-tiger interaction. Additionally, eight new tiger reserves in India are being set up. Indian officials successfully started a project to reintroduce the tigers into the Sariska Tiger Reserve. The Ranthambore National Park is often cited as a major success by Indian officials against poaching.

Russia:

The Siberian tiger was on the brink of extinction with only about 40 animals in the wild in the 1940s. Under the Soviet Union, anti-poaching controls were strict and a network of protected zones (zapovedniks) were instituted, leading to a rise in the population to several hundred. Poaching again became a problem in the 1990s, when the economy of Russia collapsed, local hunters had access to a formerly sealed off lucrative Chinese market, and logging in the region increased. While an improvement in the local economy has led to greater resources being invested in conservation efforts, an increase of economic activity has led to an increased rate of development and deforestation. The major obstacle in preserving the species is the enormous territory individual tigers require (up to 450 km2 needed by a single female). Current conservation efforts are led by local governments and NGO's in consort with international organisations, such as the World Wide Fund and the Wildlife Conservation Society. The competitive exclusion of wolves by tigers has been used by Russian conservationists to convince hunters in the Far East to tolerate the big cats, as they limit ungulate populations less than wolves, and are effective in controlling the latter's numbers. Currently, there are about 400-550 animals in the wild.

Tibet:

In Tibet, tiger and leopard pelts have traditionally been used in various ceremonies and costumes. In January 2006 the Dalai Lama preached a ruling against using, selling, or buying wild animals, their products, or derivatives. It has yet to be seen whether this will result in a long-term slump in the demand for poached tiger and leopard skins.

Rewilding:

The first attempt at rewilding was by Indian conservationist Billy Arjan Singh, who reared a zoo-born tigress named Tara, and released her in the wilds of Dudhwa National Park in 1978. This was soon followed by a large number of people being eaten by a tigress who was later shot. Government officials claim that this tigress was Tara, an assertion hotly contested by Singh and conservationists. Later on, this rewilding gained further disrepute when it was found that the local gene pool had been sullied by Tara's introduction as she was partly Siberian tiger, a fact not known at the time of release, ostensibly due to poor record-keeping at Twycross Zoo, where she had been raised.

Save China's Tigers:

The organisation Save China's Tigers, working with the Wildlife Research Centre of the State Forestry Administration of China and the Chinese Tigers South Africa Trust, secured an agreement on the reintroduction of Chinese tigers into the wild. The agreement, which was signed in Beijing on 26 November 2002, calls for the establishment of a Chinese tiger conservation model through the creation of a pilot reserve in China where indigenous wildlife, including the South China Tiger, will be reintroduced. Save China's Tigers aims to rewild the critically endangered South China Tiger by bringing a few captive-bred individuals to South Africa for rehabilitation training for them to regain their hunting instincts. At the same time, a pilot reserve in China is being set-up and the Tigers will be relocated and release back in China when the reserve in China is ready. The offspring of the trained tigers will be released into the pilot reserves in China, while the original animals will stay in South Africa to continue breeding.

The reason South Africa was chosen is because it is able to provide expertise and resources, land and game for the South China tigers. The South China Tigers of the project has since been successfully rewilded and are fully capable of hunting and surviving on their own. This project is also very successful in the breeding of these rewilded South China Tigers and 5 cubs have been born in the project, these cubs of the 2nd generation would be able to learn their survival skills from their successfully rewilded mothers directly.

It is hoped that in 2010, the Chinese year of the Tiger, the first batch of rewilded South China Tigers can be sent back to China from South Africa, and be released into the wild.

Relation with humans:

Tiger as prey:

The tiger has been one of the Big Five game animals of Asia. Tiger hunting took place on a large scale in the early nineteenth and twentieth centuries, being a recognised and admired sport by the British in colonial India as well as the maharajas and aristocratic class of the erstwhile princely states of pre-independence India. Tiger hunting was done by some hunters on foot; others sat up on machans with a goat or buffalo tied out as bait; yet others on elephant-back. In some cases, villagers beating drums were organised to drive the animals into the killing zone. Elaborate instructions were available for the skinning of tigers and there were taxidermists who specialised in the preparation of tiger skins.

Man-eating tigers:

Although humans are not regular prey for tigers, they have killed more people than any other cat, particularly in areas where population growth, logging, and farming have put pressure on tiger habitats. Most man-eating tigers are old and missing teeth, acquiring a taste for humans because of their inability to capture preferred prey. Almost all tigers that are identified as man-eaters are quickly captured, shot, or poisoned. Unlike man-eating leopards, even established man-eating tigers will seldom enter human settlements, usually remaining at village outskirts.[108] Nevertheless, attacks in human villages do occur. Man-eaters have been a particular problem in India and Bangladesh, especially in Kumaon, Garhwal and the Sundarbans mangrove swamps of Bengal, where some healthy tigers have been known to hunt humans. Because of rapid habitat loss due to climate change, tiger attacks have increased in the Sundarbans.

A female tiger Tatiana escaped from her enclosure in the San Francisco Zoo, killing one person and seriously injuring two more before being shot and killed by the police. The enclosure had walls that were lower than they were legally required to be, allowing the tiger to climb the wall and escape.

Traditional Asian medicine:

Many people in China have a belief that various tiger parts have medicinal properties, including as pain killers and aphrodisiacs. There is no scientific evidence to support these beliefs. The use of tiger parts in pharmaceutical drugs in China is already banned, and the government has made some offenses in connection with tiger poaching punishable by death. Furthermore, all trade in tiger parts is illegal under the Convention on International Trade in Endangered Species of Wild Fauna and Flora and a domestic trade ban has been in place in China since 1993. Still, there are a number of tiger farms in the country specialising in breeding the cats for profit. It is estimated that between 5,000 and 10,000 captive-bred, semi-tame animals live in these farms today.

As pets:

The Association of Zoos and Aquariums estimates that up to 12,000 tigers are being kept as private pets in the USA, significantly more than the world's entire wild population, 4,000 are believed to be in captivity in Texas alone.[citation needed]

Part of the reason for America's enormous tiger population relates to legislation. Only nineteen states have banned private ownership of tigers, fifteen require only a license, and sixteen states have no regulations at all.[citation needed]

The success of breeding programmes at American zoos and circuses led to an overabundance of cubs in the 1980s and 1990s, which drove down prices for the animals. The SPCA estimate there are now 500 lions, tigers and other big cats in private ownership just in the Houston area.[citation needed]

In the 1983 film Scarface, the protagonist, Tony Montana, aspires to obtaining all the exterior trappings of the American Dream, which in the character's opinion included keeping a pet tiger on his property.

Cultural depictions:

The tiger replaces the lion as King of the Beasts in cultures of eastern Asia, representing royalty, fearlessness and wrath. Its forehead has a marking which resembles the Chinese character, which means "king"; consequently, many cartoon depictions of tigers in China and Korea are drawn with on their forehead.[citation needed]

Of great importance in Chinese myth and culture, the tiger is one of the 12 Chinese zodiac animals. Also in various Chinese art and martial art, the tiger is depicted as an earth symbol and equal rival of the Chinese dragon- the two representing matter and spirit respectively. In fact, the Southern Chinese martial art Hung Ga is based on the movements of the Tiger and the Crane. In Imperial China, a tiger was the personification of war and often represented the highest army general (or present day defense secretary), while the emperor and empress were represented by a dragon and phoenix, respectively. The White Tiger is one of the Four Symbols of the Chinese constellations. It is sometimes called the White Tiger of the West, and it represents the west and the autumn season.

In Buddhism, it is also one of the Three Senseless Creatures, symbolising anger, with the monkey representing greed and the deer lovesickness.

The Tungusic people considered the Siberian tiger a near-deity and often referred to it as "Grandfather" or "Old man". The Udege and Nanai called it "Amba". The Manchu considered the Siberian tiger as Hu Lin, the king.

The widely worshiped Hindu goddess Durga, an aspect of Devi-Parvati, is a ten-armed warrior who rides the tigress (or lioness) Damon into battle. In southern India the god Ayyappan was associated with a tiger.

The weretiger replaces the werewolf in shapeshifting folklore in Asia; in India they were evil sorcerers while in Indonesia and Malaysia they were somewhat more benign.

The tiger continues to be a subject in literature; both Rudyard Kipling, in The Jungle Book, and William Blake, in Songs of Experience, depict the tiger as a menacing and fearful animal. In The Jungle Book, the tiger, Shere Khan, is the wicked mortal enemy of the protagonist, Mowgli. However, other depictions are more benign: Tigger, the tiger from A. A. Milne's Winnie-the-Pooh stories, is cuddly and likable. In the Man Booker Prize winning novel "Life of Pi," the protagonist, Pi Patel, sole human survivor of a ship wreck in the Pacific Ocean, befriends another survivor: a large Bengal Tiger. The famous comic strip Calvin and Hobbes features Calvin and his stuffed tiger, Hobbes. A tiger is also featured on the cover of the popular cereal Frosted Flakes (also marketed as "Frosties") bearing the name "Tony the Tiger".

The Tiger is the national animal of Bangladesh, Nepal, India (Bengal Tiger) Malaysia (Malayan Tiger), North Korea and South Korea (Siberian Tiger).

World's favourite animal:

In a poll conducted by Animal Planet, the tiger was voted the world's favourite animal, narrowly beating the dog. More than 50,000 viewers from 73 countries voted in the poll. Tigers received 21% of the vote, dogs 20%, dolphins 13%, horses 10%, lions 9%, snakes 8%, followed by elephants, chimpanzees, orangutans and whales.

Animal behaviourist Candy d'Sa, who worked with Animal Planet on the list, said: "We can relate to the tiger, as it is fierce and commanding on the outside, but noble and discerning on the inside".

Callum Rankine, international species officer at the World Wildlife Federation conservation charity, said the result gave him hope. "If people are voting tigers as their favourite animal, it means they recognise their importance, and hopefully the need to ensure their survival," he said.